OpenSSL is a toolkit that implements the Secure Sockets Layer and Transport Layer Security protocols, as well as a full-strength, general purpose cryptography library. An integer underflow flaw, leading to a buffer over-read, was found in the way OpenSSL handled DTLS application data record lengths when using a block cipher in CBC mode. A malicious DTLS client or server could use this flaw to crash its DTLS connection peer. Red Hat would like to thank the OpenSSL project for reporting this issue. Upstream acknowledges Codenomicon as the original reporter. On Red Hat Enterprise Linux 6, this update also fixes an uninitialized variable use bug, introduced by the fix for CVE-2012-0884 . This bug could possibly cause an attempt to create an encrypted message in the CMS format to fail. All OpenSSL users should upgrade to these updated packages, which contain a backported patch to resolve these issues. For the update to take effect, all services linked to the OpenSSL library must be restarted, or the system rebooted.